Twisty-Grip mod help needed (TheMan, SirPoonga, OSCAR, LilWolf, 1Up please read)

[Tiger-Heli]

I think I have a really neat concept, but I need some help to bring it to completion.  I'll try to keep this short, but unfortunately, it won't be  

Here's what I have in mind:  I got a set of (old???) Twisty-Grip plans a couple years ago.  I liked the handles, but didn't like the plastic tubing look of the controller.  I also couldn't figure out the whole concept.  I was going to build my own yoke using mouse optics and the twisty grip handles, but that idea fell through.

Then 1Up came out with his Dual Strike to SW yoke hack and I was going to go that route.  I even got the dimensions from 1Up (thanks again) and designed an enclosure for the original yoke, which I have sketches of  here:  http://www.fraggersxtreme.com/museum/Temp/yokesideview.png and http://www.fraggersxtreme.com/museum/Temp/yokefrontview.png.

However, yokes have currently been going for about $75.00 on E-bay, and those are usually with parts missing and without replacement parts available.  This is too much for a handful of games when I will have a harder time finding replacement parts later.  And I would like to leave the original yokes available for someone refurbishing an original SW cabinet.

Recently, I think I saw LilWolf post about the Twisty-Grip and I had two ideas:  First it should be possible to hack the Twisty Grip to a Dual Strike (and I now have one   )  I saw on the Twisty-Grip board that SirPoonga had the same idea.

Next it should be possible (and fairly easy) to make a $10.00 plywood box to match (or come close to) the original SW yoke center box dimensions, which I could mount around the center shaft and side shafts of the Twisty-Grip and make it look like an original SW yoke (with funny white handles).  And then I should be able to mount it to my enclosure.  BTW, this should also allow me to come up with an autocentering method which is not visible from outside the yoke.

Problem is I can't understand the design well enough to modify it.  Here's what I have so far:

The trigger-switches are also available from www.mouser.com and I don't think they tack on extra charges for small orders like digi-key does.

The things I found wrong with the Twisty-Grip Plans, I am temporarily posting at: http://www.fraggersxtreme.com/museum/Temp/Twisty%20plans.html (Note: This was originally intended to be sent to the author, so I point out a lot of typos, etc.)  If anyone has a copy of the Twisty-Grip plans and could answer these questions, I would be most grateful.

Also, I played around in Lowe's PVC pipe section last night.  It appears that 1" PVC slides into 1.25" PVC and this is the key feature of the design.  I also noticed that they carry ABS pipe in black, but don't know if they have the fittings for the handles or not, if so, I could make black handles  

I picked up a 1.5" tee and mounted the 2" coupling on top of it, and it seemed pretty wobbly.  I don't see that the 2" coupling and the 2"x1.5" reducer, which Twisty Grip calls "the Cowling" does much of anything other than hide the innards of the z-axis shaft.  If anyone who has built one could confirm?

Also, since I am using the enclosure, I shouldn't need the tee to mount the yoke to the base, which should reduce the depth considerably.

I was looking for a way to mount the unit to the wood panel and picked up a 1.5" Male Adapter.  With the threads pointed down, I noticed that a 1" tube fit through it with very slight play.  A 1.25" tube fit into it, but bottomed out, and a 1.25 inch T did not fit inside it.  These all seemed like good things, but again I don't really understand the concept enough to know if I am looking at this right.

Also, I forgot that the original design uses a 1.5x1.0 inch bushing reducer in the 1.5 inch Y-fitting (not shown in the text, but the pictures show it), and this should fit in the 1.5 inch Male Adapter, so I think I'm even more on the right track    (Means another trip to Lowe's, though  

Also I picked up a 1.5" female adapter and noticed that after I threaded it onto the male adapter there was about a 3/4-inch gap remaining.  I couldn't find a nut that would thread all the way down on the adapter, but I think I could cut the guts out of a slip nut, or even better, I could always use 3/4-MDF (with Formica) for the front panel.

So, I have the front wood sandwiched between a male and female 1.5 inch adapter.  And the end of the Female adapter will take the 1.83-inch section of 1.5-inch pipe and the 1.5-inch end cap like the original twisty-grip plans.  So all that remains is to cut a hole somewhere in the assembly for the wires to come out, and to figure out the lengths to adjust the z-axis shaft, collar, and dowel to make the assembly work with the new configuration.  I should be able to do this once I understand the design itself better.

Does anyone see any problems with this or a better way to do it?  Anyone have any tips on autocentering (I think I can use the tips from Lew's Wheels or the other wheel building sites, but I need to brush up on them!)

From what I remember, I think I can just mount an eyelet on the turning shaft and take it straight up to an eyelet on the enclosure, but I don't know how you determine spring length and tension required?

[1UP]

   OK, I'm officially dizzy now...  I don't have the plans, so I really couldn't answer any questions for ya.  Best thing to do once you have a design that SEEMS like it should work, is start building it, and make changes as you go along.  Sorry, but when you're making something new, you've got to eat the cost of prototyping and testing...  It's a choice between that, or buying it ready-made.

I had to design a whole cab from scratch (complete with rotating control panels, which only one other person has done, and very different from my design.)  It was just lots and lots of sketching, followed by a detailed computer model of the whole thing.  And by the way, I made a prototype CP first to test the concept and get real-world measurements I couldn't have gotten any other way, and now that I've finished my cab, the prototype is going in the dumper.  But it wasn't a waste, because I got very valuable info from it!  

As far as springs, all you should need to do is make some kind of pin or connector on your shaft, connect 2 springs of the same length/tension to it, and then attach the other ends to opposing points on the housing.  I have seen suitable springs at Home Depot.  You shouldn't need anything too heavy.  But make sure you have some way of limiting the movement of the yoke (bumpers or something) so you don't over-stretch the springs or snap off the pots!  

Now, an alternative to twistygrip:  Before I found my yoke, I was going to make one from scratch, and never even considered the twistygrip because it seemed too ugly and flimsy.  Then I saw Joey's Project here on BYOAC, and decided that I would go the same route, using maybe a plastic or metal electronics project enclosure (available ready made in various sizes at electronics stores) combined with some RC gears, glass door bearings, and two Happs grip assemblies.  The insides could be pots or mouse guts (I would suggest pots as most yoke-type games expect a joystick, and you already have the Dual Strike.)

Also, Xiaou2 has made his own yoke from wood, which should be helpful in designing your own.  Even made his own gears!

Hope this all helps.  Good luck.

[Xiaou2]

 Thanks for the plugs : )

 1up is correct,   it takes a lot of proto work to build something.   I made a LOT of mistakes in my design.. but now I have it down.  Unfortunatley, Its gona be a while before I can afford to finish.   Anyway,  just to note,  I had to scrap the homemade gears.   They finally fell appart (again.. prototyping! : )   I ended up using some large plastic gears at a hobby shop that I had to custom modify.

 the rear of the thing, is the same design as this:



http://www.xiaou2.homestead.com/hangon.html
look at the page for more details

 You may be able to do something simular to this with pvc.

[Minwah]

OK I'm getting more and more interested in these yokes each day, I don't think I've even used a real arcade one  

Stupid question but why do you need the gears?  I'm guessing that if you just mounted say an optic wheel on the shaft(s) it wouldn't be sensitive enough, so the gears increase the sensitivity.  Am I right?  Would MAME's sensitivity options not go high enough to work well?

I remember seeing Joey's project some time ago - it looks SO good

[Xiaou2]

 Sorry to hear that you never got to play a yoke'd game.  It makes the games controll so much more accuracte and fun.

 As for the rest..  1st off,  you dont want to use optics for yokes, as you cant reset thier position - (like picking up a mouse and putting it down).   If you had your mouse pointer in an odd position on the screen, and you started  the game, you wouldnt be able to center it.

 You have to use pots.  

 As for the gears,  well, you could use a direct means of pinning the pot to the shaft... but, yes,  sometimes, the pot may turn too much, or not enough, depending on the  shaft.  Mostly, its not enough... thus its not sensative enough.

 

[Minwah]

Yeah, I was hoping for a go in a Star Wars cockpit at the GameOn show, but it was broke

I see what you mean about optics, but surely when you start MAME, it sets the current position as 'centre' - so it should work OK ??  What I mean is, when you start a spinner (or wheel) type game eg Chamionship Sprint, the cars aren't automatically turning left or right when you begin your first go, they don't turn until you start spinning.  Since spinners work for the yoke / 270 wheel games (to an extent) would this theory not work?  You'd just have to restrict the movement as per the yoke examples already.

I just started thinking about this after noticing the optic wheel for the Y-Axis in Joey's project, why not use optics for the X-Axis too?

I figured sensitivity might be an issue with a direct drive optic thing.

Thanks for your help, please tell me if I've got it totally wrong about the optics stuff  

[Tiger-Heli]

Thanks for the replies.  Let me rephrase my original question (and then I'll prolly make 1Up dizzy again!).  I looked at the Twisty Grip Plans again.  I think the original design called for internal centering springs and that is what the extra holes are there for.  I don't expect any of this to make sense without the plans, but I'll try to explain anyway.  After trying the parts out, I think it must work the way I said in the link.  (Hopefully someone who actually built one can help me out.)

It seems clear that the Z (left-right) axis works as follows:  Rotating the Large 1.25-inch T rotates the collar, which rotates the dowel which rotates the pot shaft.  No problem.

And I am convinced the X-axis (up-down) must work like this:  Clearly the 1.25-inch spacer will not rotate inside the 1.25 inch large T.  This means that the dowel will not rotate.  Clearly the 1.0-inch X-axis shaft will rotate freely inside the 1.250-inch large T and will not rotate relative to the 1.0-inch grips.  I.e. the shaft turns with the grips.

NOW THE BIG QUESTION!!!  This means the since the X-axis dowel is stationary, the X-axis pot shaft must be stationary.  Therefore, SOMETHING must turn the X-axis pot base as the grips are rotated.  This is what has never made sense to me about the design.  The plans imply there is either a 1/2-inch dowel (length unknown) (or two 1/2-inch dowels), or a 2.88 inch long 7/8 inch dowel inside the left grip (or the left and right grips) and maybe this creates enough tension that the base of the pot is rotated along with the grips, but this seems like a flimsy way to do this.  I would think there must be some connection between the pot base and the left grip, (even if just foam tape on the mysterious dowel) but I don't know what it is?

New comments:

1Up - I am familiar with Joey's yoke design.  In fact, Joey originally sent the Twisty Grip plans to me when I was asking him about it.  IIRC, he made most of it himself from either billet aluminum or Acetal.

Minwah - Joey's yoke DID use optics on both the X and Y axis.  It worked but he said it needed a lot of gear reduction and that wasn't even enough.  He said if he were building it again, he would use pots.

Xiaou2 - awesome job on the Hang-on controller and thanks for the explanation of the Sinistar joystick in OSCAR's thread.

However, you guys both overestimate me.  I do not plan to design some intricate gear train for the yoke.  That is one of the things I like about the Twisty-Grip design.  The entire project does not require any gearing and the most expensive single items are the $10.00 (total) for the four trigger switches.  (Or the $15 for the dual strike, if you count that.)  And the design has been well reviewed, so I know it will work if I can just figure out that one little detail above.

Also, I took another trip to Lowe's yesterday and found out some helpful stuff for anyone else considering a similar project.  First, Lowe's does not carry 1" Tees in ABS, so you can't make black handles (need to check Home Depot, though).  They do carry the parts in CPVC, so you could have tan handles and Schedule 80 PVC for dark gray handles.  The schedule 80 stuff is about $2.50 for the Tees and each end cap so you end up with $15.00 in parts to make the handles as opposed to about $3.00 using PVC.  I'll stick with white (unless Depot has the ABS!).

My "mod" is simple (or else I wouldn't be attempting it :-)  Basically, what I am doing is substituting a 1.5-inch female and a 1.5 inch male adapter for the 1.5 inch Y fitting on the original design.  This allows the yoke to be anchored to an angled panel instead of the horizontal base.  Also, I found out that the PVC adapters leave about 5/8" gap when anchored down all the way (3/4" MDF should work well) but I also found a 1.5 inch ABS Male and Female adapter that leaves only a 1/8 inch gap when screwed down all the way.  (So my 3/8-inch plywood will still work.  The ABS is about 3/4-inch shorter on each piece than the PVC is.

Basically, the only changes to my mod from the original design would be to shorten the Z-axis dowel by the difference between the length of the 1.5-inch Y fitting (which I am omitting) and the total of the height of the Male fitting above the panel, the height of the female fitting below the panel, and the thickness of the panel itself.  Of course the original design didn't have anything behind the grips, so I think my grips might hit the wood, which means a longer dowel, Z-axis shaft, and Z-axis collar.  I can calculate this also, though.  (Rough guess is 3.75 inches above the panel for the center of rotation to keep the grips from hitting).  I just need to find out how the X-axis pot was attached in the original design.

My last concern is that I am not convinced that the reducer fittings and couplers are uniform between Home Depot and Lowe's (why would most people care if a coupler was 1/2-inch longer than another one, if you're just joining pipe together), so I might put some dimensions down which don't work for everyone when I write up how I made the project, but that's way down the line.

[Lilwolf]

btw, I have also been thinking about building my own starwars yoke.

One thing I considered was some of the twisty grip consepts (of PVC in PVC) but not for the hole thing.  

Then I started thinking that I should take a quick look at the plumbing section and see if I could create a twisty grip like thing with metal tubes instead... but less of them...

Or other places... automotive sections.  You might be able to find some parts that would work/


but if you were going to build your own boxes, and buy 2 $10 grips (from bob roberts)... then all you need is the ability to turn that box from the center and then rotate the handles.

So if you have a solid 'axle' for the grips, through the center box.  You have 2 rotating joints.  And you have to be able to stop them moving beyond their intended range... and you need to be able to see how far it moved.

Then you need the same for the base..

all this with both joints need to be hollow so you can bring the buttons throught.

Now I don't have the twisty plans... but I've seen the pictures they have posted so I know about how they do things....

But what I was thinking was this.  

1) have tube in tube (pvc or whatever).  Then mount the pot inside the middle (moving) tube... and clamp it to that tube pointing towards the center.  Then attach a stick/something to the rod that sticks out and attachs to the outside tube (and doesn't move).  So now when then center moves it moves the pot.

You could instead hook some gears up... but that requires a LOT more work getting everything just right.

2) to restrict movement, you need to stop the movement fromt the center.  This should be easy with slots in the outside and a pin/screw in the center.

[Minwah]

I think I understand now why not to use optics  

So, how far should the yoke turn?  I guess if you do as Lilwolf says, with the pot turning directly, then the amount of turn in the yoke will be limited by the pot (?)  Can you get pots that turn different amounts?  ie like 1 which turns 270degrees for x-axis and something else (less probably) for the y-axis.  If so, this would surely remove the need for gears.  I guess it's not that simple tho  

[RacerX]

I just ordered and received the TwistyGrip plans myself.  I'm in the VERY early stages of planning a yoke, and I wanted to have them to get ideas.  I'm not too keen on the looks of the PVC, and I want real grips.  So I'm not planning on building a TwistyGrip per se, but if I can look at my plans and answer any questions about differences between the ones you have and the ones I have, let me know.

[Lilwolf]

I think I understand now why not to use optics  

So, how far should the yoke turn?  I guess if you do as Lilwolf says, with the pot turning directly, then the amount of turn in the yoke will be limited by the pot (?)  Can you get pots that turn different amounts?  ie like 1 which turns 270degrees for x-axis and something else (less probably) for the y-axis.  If so, this would surely remove the need for gears.  I guess it's not that simple tho  

pots come in all sizes and flavors.  1/4 turn 5k pots will allow you to have a 1/4 rotation for a full arcade type analog controller.

PC's use 100k pots for their joysticks.  there is the 1up dual strike hack that is a controller that had 20k pots that only turned 1/4 (so 5k pot reading)  so you can directly connect arcade pots.

something else to note.  Pots are rated on how many turns until they die.  Some will NOT work (especially cheap ones) in a controller... becase a few months of use and it's gone.

I might try to use the pots that came in the dual strike itself.  they are small and should last a while

[rampy]

dumb question... has anyone played star wars arcade using a vanilla flight yoke?  

http://www.quickshot.com/game_controllers/prowheel.html

You'd have to push and pull the stick in and out instead of rotating the handles down/up...  or would it just not be the same...?

*shrug* (after a trackball, I must have a star wars controller next! =P )

rampy

[1UP]

dumb question... has anyone played star wars arcade using a vanilla flight yoke?  

http://www.quickshot.com/game_controllers/prowheel.html

You'd have to push and pull the stick in and out instead of rotating the handles down/up...  or would it just not be the same...?

*shrug* (after a trackball, I must have a star wars controller next! =P )

rampy

You're right, the feeling isn't the same.  Those yokes are not made for split-second response.  Remember, you use the yoke for precise aiming, not just flying.  The SW yokes were possibly the best analog control ever made because they are both responsive and stable.

As for using pots to restrict movement THIS IS NOT A GOOD IDEA!  All the analog game controls out there have some mechanical method of restricting the stick, thus sparing the pots.  Pots are used mainly for volume and brightness controls etc that are adjusted with your fingertips, and are not meant to have a great amount of force.  If you take a pot and directly attach a large, 2 handled grip to the shaft, it's a matter of seconds before you get too excited and twist the pot to the breaking point!  

Yet another reason not to use optics in a yoke: Acceleration.  Most people have mouse acceleration on in windows.  This means the mouse moves farther when you move quickly, and when you allow the controller to return to center, it may not actually be centered.  Also, SW might allow you to use a mouse, but other analog games won't.  This means if you want to use the yoke for other flying/racing games, you may be restricted in the games you can play with the yoke.  BTW, if you use a Dual Strike, it has a mouse emulation mode, so you can switch it to act as a mouse if you want, while still having analog capability...

[Tiger-Heli]

I just ordered and received the TwistyGrip plans myself.  I'm in the VERY early stages of planning a yoke, and I wanted to have them to get ideas.  I'm not too keen on the looks of the PVC, and I want real grips.  So I'm not planning on building a TwistyGrip per se, but if I can look at my plans and answer any questions about differences between the ones you have and the ones I have, let me know.

That's pretty close to what I had in mind.  If you could look at http://www.fraggersxtreme.com/museum/Temp/Twisty%20plans.html and see what you might see different in your plans that would help.  Also, I especially am trying to figure out how they hold the X-axis pot in place, if that is more obvious to you or shown in your plans.

BTW, how long ago did you order them?  They haven't returned my E-mail or posted on their msg board since April, so I didn't know if they were even really still around.

[Lilwolf]

btw, I wasn't saying to use the pots to stop the rotation at all... If it came across like that... IGRNORE ME... because it will give your controls about a week amx before they die...

But I was trying to add (after mentioning the pots) is that you have to make sure that you stop the motion before the pot stops...

BTW, I just realized that I just took a bunch of scrap metal to the dump (because I am tyring to sell my house... but damn I wish I hadn't)... it would have been perfect for creating the box around a yoke.

well... I think I'm going to the junk yard this weekend looking for some scrap metal....  

[Chris]

I was actually just thinking of starting a web page dedicated to creating a yoke design...  the TwistyGrip plans look far too involved for what needs to be done...

The Star Wars yoke is actually a VERY simple piece of hardware.  I found an excellent picture from an eBay auction once showing the internals:



From here, every moving part can be seen, and it should be clear how simple it should be to put one together.

The grips would actually the most expensive part to reproduce.  I was considering using the Happs grips, but they're $25 each.  I'll have to look at what Bob Roberts has.

Oh, and has anyone considered putting a button in the center of the yoke?  This would be perfect for Spy Hunter; I'm even considering hacking the Spy Hunter driver to flash the Van light as the ScrollLock LED, then adding a simple lamp driver to the yoke to flash an illuminated button.

The real tricky part for me is that I don't have room on my panel for a full-time yoke, so I need to devise a way of being able to mount the yoke and remove it easily.

Oh, while we're talking about adding controls... imagine adding a couple of extra buttons to play the X-Wing PC game?  That would be seriously fun with a yoke controller!  Anyone remember if the keys from that game can be remapped?

--Chris

[SirPoonga]

I was actually just thinking of starting a web page dedicated to creating a yoke design...  the TwistyGrip plans look far too involved for what needs to be done...

The twistygrip doesn't seem that involved.  It;s just a cheap and easy way to have a yoke.  Making a starwars yoke would involve metal!

[RacerX]

That's pretty close to what I had in mind.  If you could look at http://www.fraggersxtreme.com/museum/Temp/Twisty%20plans.html and see what you might see different in your plans that would help.  Also, I especially am trying to figure out how they hold the X-axis pot in place, if that is more obvious to you or shown in your plans.

BTW, how long ago did you order them?  They haven't returned my E-mail or posted on their msg board since April, so I didn't know if they were even really still around.

My plans are at home (I'm at work   ).  But I will take a look at this tonight.  I just ordered mine via PayPal and downloaded them from their site on Tuesday.  So I assume they are still around.  They just might not be checking their e-mail much these days.

[Chris]

The twistygrip doesn't seem that involved.  It;s just a cheap and easy way to have a yoke.  Making a starwars yoke would involve metal!

Have you looked at the parts list?  Yowza!



And the basic parts for a yoke don't have to be metal: a plastic electronic project box would be just about the right size for the center box; a wood dowel could be the Y-axis shaft, and the project box can mount to a base with a lazy susan bearing, giving you your X Axis.  The tricky part, again, comes back to the grips.  Bob Roberts has them with the thumb switches for $17 each:



Perhaps if TwistyGrip-style PVC were used for the grips, and the dowel, box, and lazy susan bearing for the body, a simpler, cheaper design could be obtained....  

I'm not saying that the TwistyGrip isn't an excellent piece of work; I'm simply wondering if maybe a simpler design closer to that of the real yoke is possible.  It's certainly worth exploring...

[SirPoonga]

The twistygrip doesn't seem that involved.  It;s just a cheap and easy way to have a yoke.  Making a starwars yoke would involve metal!

Have you looked at the parts list?  Yowza!

I'm not saying that the TwistyGrip isn't an excellent piece of work; I'm simply wondering if maybe a simpler design closer to that of the real yoke is possible.  It's certainly worth exploring...

Yeah, I have the plans too.
It isn;t that complicated.  You are going to be just as complicated as the real yoke.  The real yoke has a shaft througha  bushing, the twisty equivilant is pvc inside of pvc.

[1UP]

And the basic parts for a yoke don't have to be metal: a plastic electronic project box would be just about the right size for the center box; a wood dowel could be the Y-axis shaft, and the project box can mount to a base with a lazy susan bearing, giving you your X Axis.  The tricky part, again, comes back to the grips.  Bob Roberts has them with the thumb switches for $17 each:

I don't think a lazy susan bearing would work.  Remember, you've got to attach a pot to the y-axis.  You would either have to use a zip-cord glued on the inside diameter of the bearing that meshes with a gear on the pot (very difficult to align and wouldn't wear well) or you'd have to add another shaft that attaches to the main body and goes thru the lasy susan bearing, in which case you might as well use one shaft without the bearing.

Perhaps if TwistyGrip-style PVC were used for the grips, and the dowel, box, and lazy susan bearing for the body, a simpler, cheaper design could be obtained....

I would suggest using PVC or ABS pipe internally for the axes, glued to a plastic project box as the main body.  Then you could make grips from some cheapo $5 joystick handles from the bargain bin.  I think I could come up with a simpler design that would look more like a real yoke...

[RacerX]

That's pretty close to what I had in mind.  If you could look at http://www.fraggersxtreme.com/museum/Temp/Twisty%20plans.html and see what you might see different in your plans that would help.  Also, I especially am trying to figure out how they hold the X-axis pot in place, if that is more obvious to you or shown in your plans.

As far as the pipe clamp goes, I assume they are referring to something like this:  http://shop.toohome.com/html/products/product_25582.asp

The 1.5 to 1" bushing reducers are the couplers (it says so in the AKA column on the parts list).  They are on my Appendix C.  They are the only pieces with a hex end on them.

Now on to the 7/8" dowels.  My list shows one of them 6.3 inches long and another one 8.5 inches long.  My appendix C does not show the 2.88 inch one, nor does the parts list.

My parts list shows one 1/2" dowel that is 0.08 inches in length.  I'm thinking that this is actually the 2.88 inch dowel that you speak of, but I, too, am in the dark as to how it is used.  The only place I see it is on page 13.  Where it talks about how to hold the X-axis Pot in place.

8. There are two ways to hold the pot in:
1. Preferred: use the two

[Xiaou2]

Hiya,

 I used to have a prototype.  The up/down pot is turned by the handle.  The pot moves with the handle, and the dowel stays put.   It seems like an odd way to do it... but it worked fine.

[Tiger-Heli]

RacerX - Thanks for looking at the plans.  I am convinced that Appendix C has not been revised to remove the internal spring mounts (possibly intentionally as the plans mention contacting the company if you require the internal springs).  Here are the differences.

As far as the pipe clamp goes, I assume they are referring to something like this: http://shop.toohome.com/html/ products/product_25582.asp

Okay, not sure if the clamp is really required, but . . .

The 1.5 to 1" bushing reducers are the couplers (it says so in the AKA column on the parts list). They are on my Appendix C. They are the only pieces with a hex end on them.

They are not on my Appendix C, my Appendix F intro is the only place with an AKA column and it shows a dash after the reducer callout.

Now on to the 7/8" dowels. My list shows one of them 6.3 inches long and another one 8.5 inches long. My appendix C does not show the 2.88 inch one, nor does the parts list.
My parts list shows one 1/2" dowel that is 0.08 inches in length. I'm thinking that this is actually the 2.88 inch dowel that you speak of, but I, too, am in the dark as to how it is used. The only place I see it is on page 13.  Where it talks about how to hold the X-axis Pot in place.

Appendix C for me shows all three lengths (6.3, 8.45, and 2.88, but does not show diameters).  Parts list shows a 0.3 inch 7/8-inch dowel and 0.1 inch 1/2-inch dowel.  Agree only mention in text is on my page 12.

Quote:

8. There are two ways to hold the pot in:
1. Preferred: use the two 1/2" dowels to keep it from turning and slipping out.
(Just lay the 1/2" dowels inside the tube. They are perfectly measured to hold the pot using tension)
(The only reason #1 is preferred is because we don't want your skin rubbing against a bolt head)
2. Use a carriage bolt from the outside.
(You could cut the head off the bolt, and saw a screwdriver slot onto the top for a flush mount)

My plans don't have the note about cutting off the bolt head.  Good idea, but I still think you would want some super glue, threadlock, or foam tape to hold the bolt to the base of the pot!!!

My appendix C calls out seven 1/2 inch holes too. I only see 5, but two of them could be through holes to make 7 total.

Mine shows a through hole through the z-axis collar for the other two.  I think this is for the auto-centering springs.

Appendix C calls out six 3/32 holes just like yours. I only see two 3/32 holes in the base to hold the suction cups.  I'm not sure what the "pie shaped circle" is, but my Appendix C says that it is for internal springs only. It has two 3/32 holes in it too. But my plans call for an external centering spring. So I'm not sure where this would be used for internal springs.

I think the six are: 2 in the base, 1 in each suction cup, two in the dowel (for the internal springs)  My Appendix C doesn't mention that the dowel ones are for the internal springs.  My text does mention the external centering spring.  I think they originally attached to the holes in Part B and Part D.

Appendix C calls out four 11/64 holes. I see them in part B and Part D and concur that they must be through holes to make 4. My text also does not mention them. They may have been used for the internal springs back when those were included in the plans.

I concur.

Appendix C calls out four 13/64 holes. I see one on the cutting board base for the external spring. I know that there would have to be one on the bottom cross piece on the yoke for the other end of the spring to be connected to, but that bottom piece is not shown on Appendix C. It is shown in Figures 126-130.

I have no 13/64 inch holes on the cutting board base and my Figures stop at 124  

I hope something in all of this helps, but I get the feeling that the plans probably are the same as yours as I type this.

Some things have obviously been revised.  However, the procedure still seems to be very vague about the X-axis pot attachment.

OTOH, I think this can work and I appreciate all the helpful comments.  Most of all, I think the comments inspired me to "re-think it through and come up with some workable solutions."

More to come.

[Tiger-Heli]

More thoughts:  First off, while the Twisty Grip does use a fair amount of parts, it is a very simple and inexpensive design.  The PVC components of the design cost $13.35 (based on buying 5 foot sections of the straight pipe, b/c I don't think you can find anything smaller), the switches are $8.00 (for all four), The base board is $4.22 (according to the plans).  The plans estimate about $10.00 for pots and DB15 connectors, (the dual strike is $15.00, but I could also use the guts of my destroyed $2.00 Gravis Destroyer joystick.  It used 200K rather than 500K pots, but I think the Windoze calibration routine would take care of it.)

It is much simpler of a design than the gearing and alignment required in an original SW yoke.  I am not trying to reduce the cost, I am just trying to make it look more like a SW yoke.  The plastic enclosure would work for the center box, but I will probably end up using wood to add strength for the centering springs.  (or, if the dimensions work right, I might try a plastic enclosure with a wood "reinforcement".  Hmmmmn . . .

Regarding Bob Roberts and the Yoke grips - $35.00 for two grips is almost as much as the entire cost of the Twisty-Grip.  $35.00 for two grips and the cost of the Twisty Grip components is getting close to the price of a genuine used SW yoke, which is an easier hack.  Also these are the grips that were used on Assault and similar games, not SW.  I'm not saying they can't be used on a SW yoke, Joey used them on his design, but they are designed to sit on TOP of a joystick shaft and you have to plug the bottom hole and make a new hole in the side (and attaching method) to use them with a SW or Twisty yoke.

For anyone considering this design, I see several "problems" with the design, particularly with the X-axis (and to lesser extent, the Z-axis) pot mounting.  "Problems" is not the correct term as I haven't heard anyone saying that the yoke did not work after they built it, but anyway . . .

Here is what I can gather.  I believe I am correct that the X-axis dowel does not rotate (and Xaiou2 has now confirmed this).  The rotation stop is located 0.425 inch in from the spacer, which sits flush when installed in the large T.  It is located 1.32 inches inboard of the dowel and X-axis shaft.  Since the left grip T fitting mates flush against the large T, the shaft and dowel must protrude 0.895 inches (1.32-0.425) into the T for the left grip.  By symmetry, it is reasonable to assume the shaft protrudes 0.895 inches into the T for the right grip.  And since the dowel is 1 inch longer than the shaft, it protrudes 1.895 inches into the right T.  I don't have a 1-inch PVC Tee handy to know what the depth from the side fitting to the interior wall is, but I surmise it is close to 1.895.  Also I looked at one of the pots from my Destroyer joystick and the width of the base and non-rotating part of the shaft is approximately 1/2-inch.  Interestingly, 1/2-inch for the pot and 1/2-inch for the mysterious dowel equals the 1-inch difference in width that the x-axis dowel extends beyond the shaft on the right side.  This makes me think that the 1/2-inch dowel is used to hold the pot against the X-axis dowel and rotate the pot base as the grip is turned.

More to come . . .

[Tiger-Heli]

Now for the problems (and solutions) . . .

Problem 1:  I am not sure why the dowel extends into the right grip, or if it touches it.  My theories are either the dowel touches the grip to ensure the dowel remains parallel to the X-axis shaft, or the dowel does not touch the grip, but extends over to allow the old internal springs to be attached, or the dowel extends to the right grip to add weight to the right side of the grip to counteract the weight of the pot and dowel on the left side.  Whatever the reason, having a non-rotating shaft in contact with the rotating right grip seems like a bad idea to me.  I would almost definitely shorten the dowel to where it could not touch the inside of the right grip, and would be tempted to shorten it to where it did not reach the center hole, so routing wires would be easier.

Problem 2:  Especially a problem on the X-Axis, but also on the Y-axis:  The pots I looked at had about 5/16-inch of threaded shaft below the rotating shaft of the pot, and this threaded shaft is the same diameter as the rotating shaft (or a little larger diameter, which makes the problem more likely).  I see nothing in the design to keep the pot and the base shaft of the pot from sliding into the dowel.  It this happens, then assuming the dowel is able to rotate the base of the pot (see next paragraph), I don't see anything that prevents the entire pot (rather than just the shaft) from turning inside the dowel, which would mean that MAME would not know that the pot had rotated at all.  Solution:  I HIGHLY recommend that you take two of the mounting nuts that come with the pot and thread one of them halfway down the pot shaft.  Thread the other one on until it just catches the threads and stop when the top of the nut is just flush with the bottom of the rotating shaft.  Then thread the other nut up against the top nut and tighten the top nut down against it.  This creates a "jam nut" which will prevent the pot base shaft from sliding into the dowel.  (A pic is worth a thousand words here, but I don't have access to a digital cam).  Note, if the original plans don't account for this, then the dowel will need to be approximately 5/16-inch shorter.

Problem 3:  It appears that the original design relies on tension between the 1/2-inch dowel and the pot base to rotate the X-axis pot.  This does not seem like a good idea.  Solution:  I would need to check the interior dimension of the 1-inch Tee, but assuming 1/2-inch is the magic number, I would recommend getting a 1-inch dowel and cutting it down the middle into a 1/2-inch semicircle.  Use foam tape to attach the semicircular edge to the inside of the 1-inch T.  Now place a square of foam tape on the bottom of the X-axis pot (after mounting in the dowel).  Press the grip onto the shaft and this should ensure that the pot base turns with the grip.

Problem 4:  No good mention of auto-centering.  Solution (for the modified yoke only):  For either axis, it should be possible to cut a slot through the outer housing, attach an eye-bolt to the rotating shaft, and attach this via a spring to another eye-bolt, mounted internally to either the enclosure or to the center box.

***

Hopefully, what I have posted will help anyone else who is considering a similar project.  I will post data on the project when I get it completed.

Not sure of schedule.  My computer is too slow to play MAME adequately ($60.00 for a new mobo will fix that).  I would like to take some pics of the project during construction ($50.00 for a ViviCam 10 will fix that), but I need that before I build it to get the most useful pics, which slows the project down).  I don't have a HotRod type controller yet and there are more games to benefit from that than the yoke, but that's $200 in parts (ordering with some "growth room") as against $30.00 additional for the yoke and the yoke is basically my own contribution to BYOAC (nobody else has built one exactly like what I am proposing, and that's kinda neat!)

Decisions, Decisions . . .  

[Chris]

The plastic enclosure would work for the center box, but I will probably end up using wood to add strength for the centering springs.  (or, if the dimensions work right, I might try a plastic enclosure with a wood "reinforcement".  Hmmmmn . . .

What about an aluminum project box?  This might have the advantage of being modifiable into the proper shape... Time to dig into my Mouser catalog.... (Anyone know the dimensions of the hub box of a genuine SW yoke?)

[Thorn]

I was routing some wood while working on my new cab today when I suddenly thought how much the router handles resembled the yoke controls. If that router ever quits working I think I'll cut the handles off!!! Another crazy idea I guess.    

[1UP]

I was routing some wood while working on my new cab today when I suddenly thought how much the router handles resembled the yoke controls. If that router ever quits working I think I'll cut the handles off!!! Another crazy idea I guess.    

Sure, if you want a yoke with only one trigger...  Just use a couple trigger sticks!!

[Tiger-Heli]

What about an aluminum project box?  This might have the advantage of being modifiable into the proper shape... Time to dig into my Mouser catalog....

Maybe, I figured out some ways to make it work, but the box is taller than it is wide, so you end up with the removable top perpendicular to the panel wood and it would look funny.

(Anyone know the dimensions of the hub box of a genuine SW yoke?)

Yup, and I figured out an easy way to make one out of wood and formica, or wood and sheet metal.  Will post results later today or tomorrow.

Okay, I'll can the suspense!  Original was 5.25 inches tall, 4.5 inches square at the base, base comes up straight for 1.125 inches, then slopes inward so the top is 3.125x4.5.

My final design I rounded the numbers so the base starts sloping at 1.0 inch and ends up at 3x4.5, everthing else is identical.

Thanks again, 1Up, for the dimensions.

[Chris]

I'm dying to see what you come up with!  Anyone know of a source for repro yoke overlays?  I didn't see any at Arcade Renovations...

[Tiger-Heli]

I'm dying to see what you come up with!  Anyone know of a source for repro yoke overlays?  I didn't see any at Arcade Renovations...

I finished the rough plans, will have some sketches and a write-up up by the end of the day.

Only think I could find for repro overlays is in this thread (and they show up on E-bay from time to time):  http://www.arcadecontrols.org/yabbse/index.php?board=1;action=display;threadid=2666;start=0

[Tiger-Heli]

Sketches are up, see: http://www.fraggersxtreme.com/museum/Temp/twistysideview.png, http://www.fraggersxtreme.com/museum/Temp/twistyfrontview.png, and http://www.fraggersxtreme.com/museum/Temp/yokecenterbox.png

(takes me a while to focus on the front one, but the data's there  )

Details - The main enclosure sides are cut 1x10's.  I decided to use a 1x10 for the front panel (12x9.5 inches wide) so 3/4-inch wood and the PVC adapter instead of the ABS.  This is not shown on the drawing b/c it would require wider paper, and I got lazy and wanted to get this out.

The original yoke handles (again thanks, 1Up) were 7.6 inches apart at the top, 8.6 at the center, and 9.5 at the bottom.  I will make my handles 8.5 inches apart (centers) as shown in the figure.  (This will require adjusting the spacer and dowel widths from the Twisty-Grip plans).  (Also the handles are further up from the panel then the original plans (very close to the original yoke position), so these dimensions get shifted also.)  (I.e., looking at the Z-axis 1.5x1.0 inch reducer, my yoke has more shaft above the reducer and less below, and a different overall dimension).  Of course any of this can be changed once you understand the concept.

Center Box Construction- (See previous post for dimensions).  There may be easier ways to do this but this works for me.  The entire box will be covered in Wilson-Art laminate (Formica).  The side panels are cut 1x10's (1x6's, if you have the wood available).  The laminate for the side panel will be cut before it is applied so the laminate can cover the screw holes.  (Basically clamp the laminate to the cut side panel and use a Dremel to cut it flush from the back side).

The bottom panel is a 3-inch by 4.5-inch and the top panel is a 3-inch square piece of 1x (10, 6?).  The panels are attached to each side panel with two 1.5 inch #8 wood screws (8 screws total).

The panels are covered with five pieces of laminate as follows (you can use contact cement to attach the laminate):

2 - 1x4.5 inch strips (nearest to the control panel)  (Yes this extends 1/4-inch above the bottom wood).

2 - 4.3 x 4.5 inch squares (angled faces)  These will be attached to the side panels using magnetic cabinet latches (and foam tape to attach the latch plates.  This allows easy access to the panels for replacing the auto-centering spings.  You could use sheet metal or even card stock if you don't want to use laminate.  By not using a full wood panel here, you avoid having to make an angle cut in the top wood.  The red square is a 1x3 that you could use as additional support, but I don't know if there is sufficient clearance for it and I don't recommend it.

1 - 3 x 4.5 inch piece to cover the top wood.

The side panels can be glued (silicone sealant, blue RTV, etc.) to the widened spacers, as these do not rotate.  The bottom will not be glued.  I am not sure if the box can be built and then have the yoke innards built inside of it, or if you have to build the box around the yoke parts as you go along.  I also have not worked out the exact position of the shaft holes which determines how high the box sits above the panel.

Auto-centering - Z-axis - It should be possible to use a small eyebolt instead of nails to hold the dowel in place.  I may move the rotation stops down to the bottom section of the yoke, use an eyebolt with a spring, and run this to a brass cupholder, which should do autocentering quite well.

Autocentering - X-axis - The same method will NOT work here.  The dowel does not rotate.  It may be possible to slot the spacer opposite the one used for a rotation stop, mount a eyebolt to the X-axis shaft, and hook this to a brass cupholder on the box side or bottom.  The eyebolt would have to attach to the shaft and still clear the dowel, and I don't know if it would.  MAYBE you could super-glue some kind of drilled pin into the shaft to attach a spring to, but I don't know that this would work either.  I'm open to suggestions . . .

[rampy]

Just so you know...

I'll probably end up doing a arcade yoke to dual strike hack (ala 1up)... but I'm following your design progress with great interest.

I'd love an easy(ier) to make star wars yolk that looked less like a bathroom fixture (referring to original twisty yoke) =)  

So if it matters to you at all, someone's perusing this thread, if that serves as any type of encouragement...

thanks and good luck!

rampy

[1UP]

I'm dying to see what you come up with!  Anyone know of a source for repro yoke overlays?  I didn't see any at Arcade Renovations...

\

I made one for Star Wars, looks decent (nice and clean) but not exactly correct.  It's at www.1uparcade.com/images/yoke_v001.jpg  There's a hi-res scan of a ROTJ overlay on CAGA.  Take your pick.

[The Man]

  Sorry, didn't see this until today.  I've been working on completing my basement and I just recently acquired a Data East Star Wars pinball I've been restoring.

Looks like you have gone the rounds on most of your questions.  Let me know if there is something I can help you with.  I built my TwistyGrip Yoke about a 18 months ago, not sure if I remember all the problems with the instructions, but they are no where near correct.  I had to have them send me some updates sheets and still everything wasn't as they said, but I did figure most of it out.

I'm still working on my basement, so I can't even get to the blueprints right now, but I'll be happy to help you in anyway that I can.

TM

[Tiger-Heli]

Looks like you have gone the rounds on most of your questions.  Let me know if there is something I can help you with.  I built my TwistyGrip Yoke about a 18 months ago, not sure if I remember all the problems with the instructions, but they are no where near correct.  I had to have them send me some updates sheets and still everything wasn't as they said, but I did figure most of it out.

I'm still working on my basement, so I can't even get to the blueprints right now, but I'll be happy to help you in anyway that I can.

TM

Thanks for the offer.  As you said, I have figured out most of the "How" questions and am left with the "Why" questions.  Since you are the only one on here I know of with a working TwistyGrip, the unanswered questions are:

Is it necessary for the X-axis (Up-down) dowel to extend almost to the right grip, and what purpose does that serve?

How does the mysterious 1/2-inch dowel keep the X-axis pot base aligned with the left grip?

What prevents the pot shaft from sliding all the way into the dowel and slipping?

Do my changes to the design seem logical to you?

Thanks again.

[Tiger-Heli]

Auto-centering - Z-axis - It should be possible to use a small eyebolt instead of nails to hold the dowel in place.  I may move the rotation stops down to the bottom section of the yoke, use an eyebolt with a spring, and run this to a brass cupholder, which should do autocentering quite well.

Just a quick note here, I went through the plans again last night.  You can't move the rotation stops down to the bottom section of the yoke, because you still have to tie the Tee to the dowel    You can leave the top section alone and slot the bottom section of the yoke also and use the method above.

Autocentering - X-axis - . . . I'm open to suggestions . . .

Actually I came up with three options (and one pretty good one) last night.  Will post details later (real life interupts again  )

[Tiger-Heli]

I found two solutions to the X-axis (up-down) auto-centering problem.

Option 1 (preferred) - Shorten the dowel for the X-axis pot as I mentioned in a previous post.  The only purpose for this dowel AFAICT is to hold the pot shaft stationary.  Slot the spacer (and if required the large T) on the side opposite the pot shaft).  (Slot width determined to accept Eye-screw below).  Insert a short (1-inch?) section of dowel (largest that will fit) in to the X-axis shaft.  Drill the dowel and X-axis shaft to accept a small (3/16-inch) Eye-screw.  Line the holes up with the slot and tighten the Eye-screw fully (the dowel will be drawn up against the inside edge of the X-axis shaft.)  Connect this to the cupholder using a spring.  (Could also use a through eye-bolt and a washer, but you would need to slot both sides.)

Option 2 - Using regular TwistyGrip design (long dowel), slot the spacer (and if required the large T) on the side opposite the pot shaft).  (Slot width determined to accept Eye-screw below).  Home Depot has a very small (approx 1/32-inch diameter) #216 Eye-screw (fans of Left Behind will see the significance).  (Actually, this same procedure may work better with a larger diameter eye-screw.)  Somehow make a small hole in the sidewall of the X-axis shaft.  Thread the Eye-screw partially into this hole, remove the Eye-screw and cut off the tapered part of the threads, as these have less strength.  Apply thread locker to the threads, line the hole up with the slots and thread the Eye-screw in until it just clears the inside wall of the X-axis shaft.  Connect the eye-screw to the cupholder using a spring.  (Problem is I am not sure how well this will hold up or how to make it work again if it were to fail  .)

[The Man]

Is it necessary for the X-axis (Up-down) dowel to extend almost to the right grip, and what purpose does that serve?

Yes, because unlike the Y-axis dowel the dowel is stationary.  You connect the POT to the right grip (I used double sided sticky tape.  Works great) and when the grip is rotated the bottom of the POT rotates but the shaft is stationary.


How does the mysterious 1/2-inch dowel keep the X-axis pot base aligned with the left grip?

If memory serves me correctly this dowel isn't even used.  Only two dowels are used: 1st for the Y-axis that starts at the bottom of the 'T' and attaches at the bottom of the Y-axis shaft. 2nd for the X-axis attached somewhere in the 'T' (I don't remember) to the right grip.


What prevents the pot shaft from sliding all the way into the dowel and slipping?

If I understand this question, you use a setscrew to secure the POT to the shaft and the nail prevents it from moving in and out.


Do my changes to the design seem logical to you?

I haven't had time to read all of the replies.  If I have sometime on Friday, I'll look over the entire thread.


Sorry, still workin on the basement.  I have cabinets coming and I'm not ready for them

TM


P.S.  I now agree with the TwistyGrip people and do NOT use the centering feature.  I've found I don't need it and other games that I use the Yoke with didn't have this feature.  I could be wrong.